Steel 42CrMo5-6
EN 42CrMo5-6
42CrMo5-6 (1.7233, comparable to 4142) is a chromium-molybdenum quenched-and-tempered alloy steel with a defined chemistry band, used where a controlled balance of strength and toughness is needed in medium sections.
Reference datasheet — 42CrMo5-6 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the +QT condition
42CrMo5-6 tempers and conditions
42CrMo5-6 is supplied in 10 conditions, soft to hard. +QT is the default FabDigit quotes; the values on this page are for it.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick for heavy machining, cold forming or before a customer-side hardening cycle; lowest hardness supply state. | 440 | 700 | 20 | 215 HB | 44 W/m·K |
Ferrite-pearlite structure, hardness range specified | Ordered when a narrow, reproducible pre-machining hardness band is needed for automatic machining lines. | 470 | 760 | 18 | 17 HRC | 8.2 % IACS |
Treated for high shearability | Bar delivered with a capped hardness so slugs can be cold-sheared cleanly for forging or upsetting. | 490 | 780 | 17 | 20 HRC | 7.8 % IACS |
Normalized | Use to refine grain and homogenize forgings before final machining or quench-and-temper. | 520 | 820 | 16 | 22 HRC | 7.8 % IACS |
Hot rolled | Cheapest supply state when the buyer will re-heat-treat the part anyway; properties are not guaranteed. | 560 | 880 | 14 | 25 HRC | 7.8 % IACS |
Cold drawn | Bright bar with close tolerance and a straight, work-hardened surface for shafting and short-run machining. | 720 | 880 | 10 | 24 HRC | 7.8 % IACS |
tempered to a medium hardness band | Common ordering band for large shafts, flanges and pressure parts where toughness and machinability outrank hardness. | 800 | 980 | 15 | 30 HRC | — |
+QTDefault Quenched and tempered | Standard supply condition for shafts, gears and rods needing ~1000–1200 MPa with good toughness. | 850 | 1,050 | 13 | 34 HRC | — |
tempered to a higher hardness band | Chosen for gears, spindles and hydraulic rods where wear and fatigue strength matter more than machining ease. | 950 | 1,120 | 12 | 34 HRC | — |
low-temperature tempered, high strength | For small sections, tooling and high-strength fasteners; toughness and hydrogen-embrittlement margin drop sharply. | 1,250 | 1,400 | 9 | 43 HRC | — |
What is 42CrMo5-6?
42CrMo5-6 (1.7233, comparable to 4142) is a chromium-molybdenum quenched-and-tempered alloy steel with a defined chemistry band, used where a controlled balance of strength and toughness is needed in medium sections. It is supplied as bar and forging stock in +A, +S, +N, +FP, +U, +C and several +QT hardness bands from 28–32 HRC up to 40–45 HRC. In the default +QT condition it reaches 850 MPa yield, 1050 MPa tensile, 13 % elongation and 320 HB (34 HRC), with service to 400 °C. Weldability (score 35) and cold formability (score 20) are limited and there is no corrosion resistance; 42CrMo4 is the standard alternative. 42CrMo5-6 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). 42CrMo5-6 has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 88% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
What is 42CrMo5-6 used for?
- shafts
- gears
- connecting rods
- high-strength fasteners
- machine tool components
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- High strength — 850 MPa (123 ksi), better than 88% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited formability — 20/100, worse than 80% of steel grades
- Limited ductility — 13%, worse than 78% of steel grades
42CrMo5-6 properties
Typical room-temperature values for 42CrMo5-6-+QT; bars are the position among steel grades.
Physical3
42CrMo5-6 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
42CrMo5-6 has a yield strength of 850 MPa (123 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 88% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
42CrMo5-6 is rated for continuous service to 400°C (752 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
42CrMo5-6 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 42CrMo5-6 takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
42CrMo5-6's machinability is fair (45/100, worse than 65% of steel grades); weldability fair (35/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. 42CrMo5-6 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 42CrMo5-6
Is 42CrMo5-6 easy to machine?
Machine in the annealed or 28–32 HRC condition with rigid setups, coated carbide and generous coolant; above 36 HRC expect ceramic/CBN finishing and heavy tool wear.
Can 42CrMo5-6 be welded?
Weldable only with 150–300 °C preheat, low-hydrogen consumables and a 600–650 °C post-weld temper; avoid welding fully hardened sections.
Can 42CrMo5-6 be formed, bent or molded?
Hot forge at 1050–1200 °C with slow cooling to avoid quench cracks; cold forming is limited to the +A/+S conditions.
42CrMo5-6 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C0.42 % nominal, basis of the grade name | 0.38 – 0.45 | 0.42 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.03 | 0.02 |
| Sresulphurized (+S-type) variants run 0.020–0.040 for machinability | ≤ 0.04 | 0.02 |
| Crricher than 42CrMo4 for hardenability | 1.1 – 1.4 | 1.25 |
| Moraises temper resistance and cuts temper embrittlement | 0.5 – 0.7 | 0.6 |
| Niresidual | ≤ 0.4 | |
| Fe | balance |
What surface finishes work on 42CrMo5-6?
No anodizing — use black oxide, phosphate, zinc or Ni plating (bake for hydrogen relief), hard chrome for rods, or gas/plasma nitriding for 600–700 HV surfaces.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 42CrMo5-6 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.7233
- Similar grades
- 4142
How much does 42CrMo5-6 cost?
42CrMo5-6 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
42CrMo5-6 — frequently asked
What is 42CrMo5-6 used for?
42CrMo5-6 is typically used for shafts, gears, connecting rods, high-strength fasteners and machine tool components. In short: controlled-chemistry 42CrMo grade; supplied in defined QT bands; nitrides to 600–700 HV.
What is the yield strength of 42CrMo5-6?
42CrMo5-6 has a typical yield strength of 850 MPa (123 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 88% of steel grades. Strength varies by condition: see the 10 listed tempers.
Is 42CrMo5-6 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed or 28–32 HRC condition with rigid setups, coated carbide and generous coolant; above 36 HRC expect ceramic/CBN finishing and heavy tool wear.
Can 42CrMo5-6 be welded?
With care — weldability is rated fair (35/100). Weldable only with 150–300 °C preheat, low-hydrogen consumables and a 600–650 °C post-weld temper; avoid welding fully hardened sections.
What surface finishes work on 42CrMo5-6?
No anodizing — use black oxide, phosphate, zinc or Ni plating (bake for hydrogen relief), hard chrome for rods, or gas/plasma nitriding for 600–700 HV surfaces.
Can 42CrMo5-6 be formed, bent or molded?
Hot forge at 1050–1200 °C with slow cooling to avoid quench cracks; cold forming is limited to the +A/+S conditions.
What is the maximum service temperature of 42CrMo5-6?
42CrMo5-6 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 42CrMo5-6 cost?
42CrMo5-6 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10083-3 Steels for quenching and tempering — Alloy steels — CEN (2006)
- EN 10250-3 Open die steel forgings — Alloy special steels — CEN (1999)
- Stahlschlüssel / Key to Steel (W.-Nr. 1.7233) — Verlag Stahlschlüssel Wegst (2019)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19: Fatigue and Fracture — ASM International (1996)
- GB/T 3077 (42CrMo) — SAC (2015)
- SAE J404 / ASTM A29 (4142 chemistry) — SAE / ASTM (2020)
- Mysteel / SMM (2025)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.